1. Field of the Invention
The present invention relates to a plasma display device and more specifically to a plasma display apparatus that prevents a burn-in on the panel.
2. Description of the Prior Art
Conventionally, there is a screen saver function that prevents a burn-in on a screen by shifting an image being displayed up, down, right, and left on the screen by the specified number of pixels at regular intervals. The screen saver shifts the image being displayed at a predetermined interval, and therefore the user can set the shifting interval.
Also, as a technology to prevent a burn-in on a panel when a still image continues to be displayed, there is known the technology to display a screen saver produced from an video image, as disclosed in Japanese Patent Laid-Open No. 2004-015288 (Patent document 1).
Furthermore, for prevention of a burn-in when an image including moving portions is being displayed, there is known the technology to prevent a burn-in on a screen by lowering the brightness of a picture signal for the still portion of the image, as disclosed in Japanese Patent Laid-Open No. 2003-308041 (Patent document 2).
The prior arts described above have the following problems:
Even though the image shifting interval can be set by the user, the once-set interval will not change and thus may become inappropriate depending on broadcast program, etc.
Regarding the technology of displaying a screen saver produced from a video image, an image the user is viewing may be interrupted and consequently the image the user needs to see will not be displayed.
As for the technology to lower the brightness of a picture signal, part of the image is darkened and the viewer may feel uncomfortable with a change in the image.